diff --git a/src/configure b/src/configure
index 5524483a6..51c53dfa0 100755
--- a/src/configure
+++ b/src/configure
@@ -1334,7 +1334,7 @@ Optional Features:
                           on Intel)
   --enable-unicode        enable support for unicode (default=NO)
   --enable-longdouble     include support for long double (default=NO)
-  --enable-c99-complex    include support for C complex type (default=NO)
+  --enable-c99complex     include support for C complex type (default=NO)
   --enable-hierarchical-packages
                           hierarchical package names (default=YES)
   --enable-asmapply       enable optimizations written in assembler
diff --git a/src/configure.in b/src/configure.in
index 3082b4c75..2f4c5fd73 100644
--- a/src/configure.in
+++ b/src/configure.in
@@ -177,7 +177,7 @@ AC_ARG_ENABLE(longdouble,
   [enable_longdouble=${enableval}], [enable_longdouble=no])
 
 AC_ARG_ENABLE(c99complex,
-  AS_HELP_STRING( [--enable-c99-complex],
+  AS_HELP_STRING( [--enable-c99complex],
                   [include support for C complex type]
                   [(default=NO)]),
   [enable_c99complex=${enableval}], [enable_c99complex=no])